[1] The defendant first assigns as error the admission of the testimony of two officers that the breathalyzer was administered to the defendant at 1:05 p.m. when the written breathalyzer record indicated that it was administered at 12:15 p.m. The defendant contends that this violated the best evidence rule. We do not agree.
The best evidence rule indicates that a writing is the best evidence of its contents. The rule does not apply “to writings *50when their contents are not in question or when they are only ‘collateral’ to the issues in the case.” 2 Stansbury, N.C. Evidence (Brandis Rev. 1973) § 190, p. 100. Additionally, “if a fact has an existence independent of the terms of any writing, the best evidence rule does not prevent proof of such fact by the oral testimony of a witness having knowledge of [that fact].” 2 Stansbury, N.C. Evidence (Brandis Rev. 1973) § 191, n. 24, p. 103.
In the present case, the contents of a writing are not in question. The original breathalyzer record was introduced into evidence, and it is undisputed that it indicated the test was administered at 12:15 p.m. The time at which the breathalyzer test was given was a fact which had an existence independent of the words on the record. The knowledge of the officers concerning this fact arose from their personal observations and experiences rather than from the writing. In such cases, the best evidence rule does not apply. State v. Branch, 288 N.C. 514, 220 S.E. 2d 495 (1975); State v. Cornell, 281 N.C. 20, 187 S.E. 2d 768 (1972); State v. Fox, 277 N.C. 1, 175 S.E. 2d 561 (1970).
[2] The defendant next assigns as error the trial court’s denial of his motion for a mistrial. The motion was made when it was learned that the breathalyzer operator had talked to one of the jurors during a recess. A hearing was then conducted concerning the incident, and both the State and the defendant examined the breathalyzer operator concerning the conversation with the juror. The trial court found that a conversation had taken place, that it concerned, the association of the two with a softball team some five years earlier, that the case was not discussed and that the conversation would not influence the juror. The trial court then denied the defendant’s motion for a mistrial.
A motion for mistrial should be granted when an occurrence during the trial results “in substantial and irreparable prejudice to the defendant’s case.” G.S. 15A-1061. The decision as to whether substantial and irreparable prejudice has occurred lies within the court’s discretion and, absent a showing of abuse of that discretion, the decision of the trial court will not be disturbed on appeal. State v. Sneeden, 274 N.C. 498, 164 S.E. 2d 190 (1968). Although the conversation between the breathalyzer operator and the juror was improper .and should not have occurred, there has been no showing that the trial court abused its *51discretion or that the conversation had a prejudicial effect on the outcome of the case. See State v. Johnson, 295 N.C. 227, 244 S.E. 2d 391 (1978). This assignment of error is overruled.
[3] The defendant also assigns as error the failure of the trial court to grant his motion to have a bag removed from the view of the jury during his trial. The bag, which apparently was a brown paper bag, was never introduced into evidence. The defendant contends, however, that its presence in the courtroom was prejudicial to him. We do not agree.
A brown paper bag is not in and of itself capable of arousing prejudice among the members of a jury. The existence of a bag was not an essential link in the development of the State’s case. Nothing in the record tends to indicate that the jury was informed of the actual contents of the bag in the courtroom or that the trial court was ever called upon to rule on the issue of its admissibility in evidence. The denial of the motion did not prevent the defendant from receiving a fair trial. See State v. Carter, 17 N.C. App. 234, 193 S.E. 2d 281 (1972), cert. denied, 283 N.C. 107, 194 S.E. 2d 634 (1973).
[4] The defendant additionally assigns as error the failure of the trial court to grant his motion for a mistrial after the arresting officer testified as to statements made by the defendant’s uncle. The arresting officer indicated that, when he went to the vehicle of the defendant’s uncle and removed the paper bag the defendant had placed there, the defendant’s uncle said, “It’s not mine. I don’t know nothing about it.” The defendant objected to the statement and the objection was sustained. The jury was then instructed to disregard what they had heard concerning this matter. Since any prejudicial effect of the statement was overcome by the prompt instruction of the trial court, the motion for mistrial was properly denied.
[5] The defendant further contends that the trial court failed to impartially set forth the evidence in its charge to the jury. The trial court was required to state the evidence to the extent necessary to explain the application of the law to the evidence. G.S. 15A-1232. Due process requires that the evidence be reviewed in a fair and impartial manner. However, objections to the trial court’s review of the evidence must be made before the jury retires in order that the trial court may have an opportunity for *52correction. If such objections are not timely made, they are deemed to have been waived and will not be considered on appeal. State v. Virgil, 276 N.C. 217, 172 S.E. 2d 28 (1970). Nevertheless, we have reviewed the charge in its entirety and find no reversible error.
The defendant presented other assignments of error which we have reviewed and find to be without merit.
The defendant received a fair trial free from prejudicial error, and we find
No error.
Judges CLARK and WEBB concur.